1. Field of the Invention
The present invention relates generally to driveline coupler devices for connecting drive train components. In particular, the present invention relates to driveline couplers for connecting driveline components that operate under high torque conditions, such as the tower drivelines of sprinkler irrigation systems.
2. Description of the Related Art
Sprinkler irrigation systems are widely used throughout the world to provide water for agricultural purposes in arid regions. Typically, such systems include a series of spaced support towers connected by truss sections that support an elevated water distribution pipe between the towers. In center pivot systems, the water distribution pipe extends radially from a central pivot communicating with a pressurized water supply. In linear move irrigation systems, the water distribution pipe extends laterally from a canal feed or hose drag system that provides a pressurized water supply.
Water passing through the distribution pipe is forced out through a number of sprinkler heads, spray guns, drop nozzles, and the like, spaced along the length of the pipe. Each tower in the system is supported on wheels that are driven at slow speeds to move the tower in a circular path about the central pivot, or a linear path in the case of linear move systems, to thereby irrigate a large tract of land.
A number of drive assemblies have been developed for driving the support wheels of sprinkler irrigation systems. The most common drive assembly includes an electric motor connected to a center gear drive assembly, a first wheel gear assembly coupled to the center gear drive assembly by a first drive shaft, and a second wheel gear assembly coupled to an opposite side of the center gear drive assembly by a second drive shaft. Each of the first and second drive shafts typically has a driveline coupler at each end that allows the shafts to be quickly and easily pulled apart and put back together to facilitate field maintenance and/or towing from field to field.
A conventional driveline coupler used by many sprinkler manufacturers is provided by Universal Motion Components, Co. (xe2x80x9cUMCxe2x80x9d) of Costa Mesa, Calif. This conventional driveline coupler has a pair of yoke members secured to opposing ends of two shafts to be coupled together. The yoke members have generally U-shaped ends that mesh with each other in a manner similar to a conventional universal joint assembly. A rubber member having four arms that extend outwardly from a center section is placed between the yoke members. In operation, the rotational torque in the driveline is transmitted through the driveline coupler by the U-shaped ends of the yoke members engaging and being engaged by the arms of the rubber member, respectively.
The conventional driveline coupler described above is now widely used in the drive trains of sprinkler irrigation systems because it provides a flexible, convenient, and reliable system to couple and uncouple a drive shaft. However, this conventional driveline coupler tends to fail under very high loads and extreme duty torque conditions, resulting in downtime and increased maintenance cost of the sprinkler system. Thus, there is a need in the industry for an improved driveline coupler suitable for use in irrigation sprinkler systems and the like.
It is an object of the present invention to provide an improved driveline coupler that provides a more reliable, extreme duty connection for drive train components.
It is a further object of the present invention to provide an improved driveline coupler that is capable of transmitting a higher amount of torque than the conventional driveline coupler described above.
It is a still further object of the present invention to provide an improved driveline coupler that is economical to manufacture, efficient in use, capable of a long operating life, and particularly well suited for use in sprinkler irrigation systems.
According to a broad aspect of the present invention, a high torque driveline coupler is provided, comprising: a first yoke assembly having a first plurality of axially extending legs extending from a base portion; a second yoke assembly having a second plurality of axially extending legs extending from a base portion, the legs of the second yoke assembly being configured to intermesh with the legs of the first yoke assembly to transmit rotational torque through the coupler; a rubber member having a center portion and a plurality of arms extending radially outwardly from the center portion, the rubber member being configured to fit between the first and second yoke assemblies with the arms of the rubber member extending between the intermeshed legs of the yoke assemblies; and an alignment system for aligning the rubber member with the first yoke assembly. The alignment system comprises a first recess formed in the center portion of the rubber member and a first projection secured to the base portion of the first yoke assembly. The first projection is shaped to fit snugly within the first recess to keep the rubber member substantially aligned with the first yoke assembly.
According to another broad aspect of the present invention, a sprinkler irrigation system is provided, comprising: at least one support tower assembly for supporting an irrigation pipe above a field to be irrigated, the support tower assembly having a drive motor, at least one wheel assembly, and a drive connection for transferring rotational energy from the drive motor to the wheel assembly. The drive connection comprises a driveline coupler having first and second yoke assemblies with intermeshed pairs of legs, a floating member with radially extending arms positioned between the intermeshed legs, and an alignment system for aligning the floating member with the yoke assemblies. The alignment system comprises a first recess formed in a center portion of the floating member and a first projection extending from: the first yoke assembly toward the first recess, the first projection being shaped to fit snugly within the first recess.
Numerous other objects and advantages of the present invention will be apparent to those skilled in this art from the following description wherein there is shown and described a preferred embodiment of the present invention, simply by way of illustration of one of the modes best suited to carry out the invention. As will be realized, the invention is capable of other different embodiments, and its several details are capable of modification in various obvious aspects without departing from the invention. Accordingly, the drawings and description should be regarded as illustrative in nature and not restrictive.